1. Field of the Invention
The present invention relates to a laundry dryer, and more particularly, to a laundry dryer which can improve a capability for drying laundry according to a drying load, and a method for controlling a drying course of the laundry dryer.
2. Discussion of the Related Art
In general, the laundry dryer dries laundry by supplying hot air to a drum. There are an exhaust type laundry dryer, and a condensing laundry type dryer depending on a method for processing wet air formed in a drying course.
The exhaust type laundry dryer discharges the wet air from the drum to an outside of the laundry dryer, and the condensing type laundry dryer condenses moisture in the wet air from the drum to remove the moisture from the wet air, and forwards dry air having the moisture removed therefrom to the drum again for circulation.
The laundry dryer controls an entire drying course according to a dryness of the drying object. In general, as means for sensing the dryness of the drying object, a electrode sensor is mounted on a lower side of a front of the drum.
In general, the electrode sensor has two metal plates arranged in parallel, for sensing the dryness of laundry from a difference of impedances between opposite metal plates generated according to moisture content of the drying object when the drying object is brought into contact with the opposite metal plates at the same time, and forwards the dryness in a voltage signal.
That is, a microprocessor which controls a general dryer system receives the voltage signal from the electrode sensor, determines the dryness of the drying object, and controls operation of the dryer according to this.
However, the related art laundry dryer has a problem in that a laundry sticking phenomenon takes place, i.e., a phenomenon in which the drying object is restricted at a rear of the drum or sticks to a surface of the drum in a case an amount of the laundry is small, resulting in failure of uniform drying, to fail regular drying.
The related art dryer is failed to provide means for determining the laundry amount, permitting the related art dryer to control the drying course with reference to the dryness of the drying object merely, but not with reference to a load.